ABHYANKAR 82nd BIRTHDAY CONFERENCE
SPEAKER: Dale Cutkoski (Missouri)
TITLE: Asymptotic Multiplicities |
ABSTRACT: We prove that limits of multiplicities associated to graded families
of ideals exist under very general conditions. Most of our results hold for
reduced excellent equicharacteristic local rings, with perfect residue fields.
We give a number of applications, including a "volume = multiplicity" formula,
generalizing the formula of Lazarsfeld and Mustata, and a proof that the
epsilon multiplicity of Ulrich and Validashti exists as a limit for ideals
in rather general rings, including analytic local domains. We also prove an
asymptotic "additivity formula" for limits of multiplicities, and a formula
on limiting growth of valuations, which answers a question posed by the author,
Kia Dalili and Olga Kashcheyeva. Our proofs are inspired by a philosophy of
Okounkov, for computing limits of multiplicities as the volume of a slice of
an appropriate cone generated by a semigroup determined by an appropriate
filtration on a family of algebraic objects.